1. Field of the Invention
The invention relates to a brace for a tool head, in particular to a brace for a tool having an elongated handle and a working head elongated perpendicular to the handle. A push broom is an example of such a tool. Typically, the elongated handle terminates in a threaded portion and is screwed into a reciprocal threaded socket in the working head for attachment of the handle to the head.
2. Prior Art
A threaded attachment of a handle and a broom head is prone to loosen during normal use of the broom, for example due to striking of the head against obstructions, and particularly where an impact is spaced from the axis of the handle, e.g., at the lateral end of the broom head. Furthermore, the broom-head is typically made of wood. Often the threads become broken, especially during heavy use of the broom, because wooden threads do not provide an inherently strong connection. Inasmuch as the threads in the head must be coarse to be formed in wood, and there is usually room for only a few turns, the threads wear and the connection loosens. Alternative connections for the handle to the head include holding the head against the handle by friction, such as when using a clamp to clamp the handle to the head, or by a pin fastening transversely through the handle and a socket formed in the head.
It is frequently advantageous for tools such as push brooms to have quite large working heads, for covering a wide swath. The broom head may contain a great number of heavy-duty bristles, affixed in or to a downward facing planar surface of the broom head. The handle, on the other hand, is cylindrical in shape and generally relatively thin, e.g., one inch or 2.5cm in diameter. The size, weight and configuration of the working head as compared to the handle can bring undue stresses to bear on the handle, especially at the handle-to-head connection. In use, the friction of the bristles on a surface during sweeping, as well as collisions by the broom head with obstacles, place great forces on the handle and the handle-to-head connection. Furthermore, as noted above, where the handle-to-head connection is a threaded fit, the handle is apt to unscrew from the head resulting from such forces of use.
The large lateral elongation of the broom head relative to the longitudinal axis of the handle is such that forces applied at the lateral ends of the broom head act with a large moment arm on the connection of the handle and the broom head. It is therefore known to provide a brace for bracing the head-to-handle connection. The intention of such braces is to mount rigid buttressing members between points on the broom head that are laterally spaced from the handle, to one or more points on the handle that are spaced along the handle from the thread or other connection of the end of the handle and the broom head. These rigid buttressing members resist tension and compression, and thus support the broom head relative to the handle, typically perpendicularly. Whereas without such braces the center of the moment arm or the fulcrum with respect to impacts against the broom head is localized at the threaded connection, the braces provide a secondary fulcrum in addition to the existing fulcrum at the handle-to-head connection. Typically this secondary fulcrum is defined at a point on the handle a number of inches up the handle from the head.
In order to define a secondary fulcrum, it is known to provide a pair of braces for attachment to a tool such as a push broom. Each brace typically has a flange for attachment against the top of the broom head. The flanges can have holes for accepting a screw for screwing the flange of the brace to the broom head. The flanges are fixed on the broom head on opposite sides of the handle-to-head junction, equidistant from the junction. The brace has a leg portion rising from the flange and angled towards the handle. Each brace terminates in a handle connection arm disposed essentially perpendicular to the broom head. The two arms have oppositely facing circular humps that when placed in opposition, define a collar with an annular opening for frictional attachment around the handle. Nuts and bolts can be used to secure the arms about the handle, the handle depending through the annular opening and the nuts and bolts urging the annular collar tightly around the handle.
The brace as described above generally satisfies the requirement that the head be braced to the handle by members operable to resist tension and compression. However, nothing prohibits rotation of the handle within the annular opening. The handle is relatively free to unscrew from the head during use, and loosening of the threaded coupling of the handle and the broom head accelerates deterioration of the joint notwithstanding the braces.
Furthermore, such braces typically are assembled to the tool, such as a push broom, by the purchaser of the push broom. The assembly required such as fastening the flanges to the head using screws and affixing the arms about the handle using nuts and bolts presents an inconvenience to a purchaser, especially one not adept at using tools, and leaves the possibility of substantial variations in the tightness (and effectiveness) of the brace members. A purchaser faced with the inconvenience of such assembly may decide to forego attaching the brace to the tool, which accelerates the damage or destruction of the tool during regular use.
It would be desirable to provide a brace for a tool, such as a push broom, that can be quickly and easily assembled to the push broom by a purchaser of a push broom, and which is inherently effective to provide tight structural support for the broom head. Additionally, it is desirable to provide a brace for a push broom which can be attached to the push broom without substantial need for tools.